The invention relates to sealing a shaft of a turbo machine. Specifically, the invention pertains to an arrangement with a throw-off ring assigned to a shaft bearing and with a seal assigned to a sealing gap and having a seal housing, in particular for turbomachines.
Particularly where turbomachines are concerned, as is known, the seal between shaft and housing, said seal being designed, for example, as a gap, slide-ring or brush-type seal, must be contactless because of the high circumferential speed.
Furthermore, direct contact between the medium to be sealed off, for example lubricant, and specific structural elements of the seal leads, as a result of contamination and/or chemical changes, to deposits, such as dirt and/or oil-carbon deposits on the seal elements. Experience has shown that this is detrimental to the sealing function and often results in the failure of the seal.
An object of the invention is to provide a novel arrangement of the type initially mentioned, in particular for turbomachines, the design and arrangement of which allows trouble-free operation in all the operating states of the turbomachine equipped with it, including during the standstill of the latter.
Proceeding from an arrangement of the type initially mentioned, this object is achieved, according to the invention, in that the mutually confronting regions of the seal housing and of the throw-off ring are designed initially to run radially and subsequently conically outward and, enclosing an annular gap between them, are arranged on the associated structural element in such a way that, during the rotation of one of the structural parts, the medium entering the annular gap has imparted to it a turbulent flow, by means of which heavy constituents contained in the medium are centrifuged out.
By structural parts, such as the seal housing and throw-off ring, present in any case per se, being designed and arranged according to the invention, the feared dirt and/or oil-carbon deposit on seal elements and the adverse consequences associated with this are reliably avoided.
According to a further feature of the invention, an annular groove and a projection are arranged on the seal housing.
By virtue of this measure, when the arrangement is at a standstill, oil running down on the walls of the sealed chamber receiving the arrangement is prevented from penetrating into the seal.
The design according to the invention of the arrangement is surprisingly simple and, in all operating states, reliably ensures the discharge of media located in the bearing chamber, in particular of oil mist and of the heavy constituents, contained in it, of dirt and lubricating-oil droplets, so that deposits in the region of a seal which lead to the failure of the latter are prevented in all the operating states of the turbomachine equipped with it.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.